Ferromagnetism occurs when electron magnetic dipoles in a material are aligned, causing their individual fields to add up and result in a large net magnetic field even without an external field. Ferromagnetically coupled refers to two interacting magnetic centers, like two Cu2+ ions, having their magnetic moments aligned in the same direction. Antiferromagnetism is the opposite, with magnetic moments anti-parallel aligned and resulting in low or zero net magnetization. Antiferromagnetically coupled means two magnetic centers have anti-parallel magnetic moments. Ferrimagnetism occurs in materials with multiple sublattices where not all magnetic interactions between sublattices cancel out, resulting in a net magnetic moment. Ferrimagnetically

1. Where possible, give definitions/explanations for each of the following. If not possible
explain what is wrong with the terminology.
(a) Ferromagnetism and ferromagnetically coupled – and the distinction between the two
terms.
(b) Antiferromagnetism and antiferromagnetically coupled – and the distinction between
the two terms.
(c) Ferrimagnetism and ferrimagnetically coupled – and the distinction between the two
terms.
Solution
Ferromagnetism -
Electron has a magnetic dipole moment, i.e., it behaves like a tiny magnet, producing a magnetic
field. Due to its quantum nature, the spin of the electron can be in one of only two states; with
the magnetic field either pointing "up" or "down". When these magnetic dipoles in a piece of
matter are aligned, (point in the same direction) their individually tiny magnetic fields add
together to create a much larger macroscopic field resulting in large net magnetization even in
the absence of a magnetic field.
Ferromagnetically coupled -
The term us used in the explanation of molecular magnetic interactions. If in a molecule there
exist two interacting magnetic centers (eg. two Cu2+ ions in direct interaction or bridged a
ligand). The two election can be aligned in same direction in the molecule, resulting a higher
magnetic moment - termed as ferromagnetically coupled metal centers. The interaction is termed
as ferromagnetic coupling.
Antiferromagnetism -
It is the opposite of ferromagnetism in which the magnetic elections are aligned anti-parallel
resulting very low or zero net magnetization.
Antiferromagnetically coupled -

2. Opposite to ferromagnetically coupled, in which the elections in the two magnetic centers are
aligned anti-parallel to each other, resulting in lower magnetic moment for the compound.
Ferrimagnetism -
It a crystal, the lattice are composed of multiple sub lattices, and if a magnetic ion is located in a
sub lattice and which is interacting with other magnetic centers in nearby sub lattice by indirect
or superexchange interactions, results in anti-parallel alignment of spins between two sub lattice.
If the interactions are not cancelled each other, results a net magnetic moment. The phenomena
is known as ferrimagnetism.
Ferrimagnetically coupled,-
The coupling interaction on spin centers in a crystal of a inorganic molecule, are coupled each
other and resulting to a net magnetic moment- in known as ferrimagnetically coupled.